The purpose of this research is to quantitatively describe the face in persons with hypohidrotic ectodermal dysplasia (HED). The techniques used to accomplish this are cephalometry and anthropometry. The long range objective of this research is to provide a craniofacial pattern profile consisting of discriminant variables describing the face which will allow the differential diagnosis of multiple craniofacial syndromes. The more immediate objective is to differentiate the facial phenotype in the two different modes of inheritance of HED in order to provide precise genetic counseling. The above objectives will be achieved in the following way. First, a series of 50 families in which there are one or more HED affecteds will be recruited. These persons will received a detailed physical examination justifying clinical classification as HED. Next, the pedigrees of these families will be grouped as characteristic of either X-linked or autosomal recessive inheritance. Affected subjects will have their facial dimensions determined by a series of PA and lateral cephalometric variables and anthropometric variables. These variables will be subjected to cluster analysis and a multivariate discriminant function analysis. These analyses will delineate those variables which characterize the face of affecteds. Results will be compared and contrasted with the unaffected normal family members in the same pedigrees and a large random control data base. Finally, the heterozygrous gene carriers (identified by both) their clinical features and pedigree analysis) will also have their facial variables quantitated and compared to affecteds and normals. In this fashion soft and hard tissue variables characterizing the face in the two different heritable types of HED will be described and used to provide genetic counseling for persons at risk to transmit this trait to their offspring.